PURPOSE: To obtain a steel sheet for machine structural use extremely high in tensile strength by specifying the cooling rate and tempering temp. after hot rolling in steel having a specified compsn. in which the content of Mn and P is reduced, the content of Mo and Ni is increased and Ti and Nb are added.

CONSTITUTION: The steel contg., by weight, 0.15 to 0.50% C, ≤0.2% Si, ≤0.6% Mn, ≤0.015% P, ≤0.02% S, 0.1 to 3.0% Cr, 0.2 to 1.2% Mo, 0.005 to 1.0% Al and ≤0.03% N and furthermore contg. one or more kinds among 0.20<V≤0.50, 0.05<Ti≤0.50 and 0.05<Nb≤0.50, and the balance Fe is used. This steel is subjected to hot rolling, is thereafter cooled under the conditions satisfying Kl≤130 defined by formulae I and II (unit: μm, [%X]: the wt.% of element X and CR: the cooling rate of the steel) and is thereafter subjected to spheroidizing. After that, the steel is formed into a prescribed shape by cold working, and next, at the time of subjecting it to hardening and tempering treatment, the tempering is executed at ≥400°C. By this method, the steel for machine structural use having ≥125kgf/mm2 tensile strength and excellent in delayed fracture resistance can be obtd.